1. Field of the Invention
The invention relates generally to printing systems and more specifically relates to printing systems having multiple energy consumption states and to methods and apparatus for automatically adjusting power consumption based on a usage profile of previous usage of the printing system.
2. Discussion of Related Art
Many printing systems utilize substantial power in operation. For example, electrophotographic (e.g., “laser”) printers typically have heated fuser rolls for fusing toner particles to paper and consume significant power. Larger printing systems (e.g., “production printing systems”) may utilize substantial power for operating motors involved in moving large volumes of paper through the printing system.
It is generally known in the art to provide power saving modes in such printing systems. As presently practiced, power saving modes are typically invoked in response to detecting a sufficient duration of idle time for the printing system. Sometimes the duration of the idle period may be reconfigured by a user to adapt to a user's requirements. For example, in a power saving mode the heated fuser of an electrophotographic printing system may be turned off or cooled to a lower temperature to conserve power after detecting an idle period of sufficient duration.
Once a printing system enters a power saving mode it can require significant time to bring the printing system back to a full power ready state. For example, re-heating the fuser back to an appropriate temperature for normal operation can require substantial time. The time required to restore a printing system to a ready state from a power saving mode may vary widely depending on the printer but in many cases can be quite substantial.
Though power saving may be important in many environments it can be a significant roadblock to user productivity in that a user may need to print a document quickly but the printing system is in a low power mode and requires substantial startup time to return to a ready mode. In addition to the possible loss of productivity, users can be annoyed by the lengthy delay in waiting for the printing system to return to a ready mode while they are waiting to retrieve a printed document.
The same issues apply to other systems that print documents such as photocopy systems and multi-function devices (e.g., multi-function printers or MFPs). Thus as used herein, “printing system” or “printing device” or simply “printer” refers to any device adapted to generate printed output. The printed output may be generated based on data received from an attached computing system (such as in the case of a computer printer or an MFP device) or may be generated from a scanned digital copy of an original printed document (e.g., as in a photocopier system).
Thus, it is an ongoing challenge to manage power consumption of a printing system while reducing wasted user time and loss of productivity.